Epigenetics: Dawkins’ “selfish gene” discredited by still more scientists you should have heard of
|December 5, 2013||Posted by News under Darwinism, Epigenetics|
You’ll need two coffee breaks to read David Dobbs’ 5500-word article in Aeon, but it’s one of the top ten to read for this year.
“Die, selfish gene, die” can be distilled (which is no substitute for reading it) into a prologue and five acts:
First, many life forms change dramatically without any changes in their genes; for example, the grasshopper transforms itself into the locust when the expression of its genes changes—epigenetics. Contrary to neo-Darwinism, nature is not slowly, daily and hourly, adding things up; environment pressures can quickly change how genes are expressed.
This gene-centric view, as it is known, is the one you learnt in high school. It’s the one you hear or read of in almost every popular account of how genes create traits and drive evolution. It comes from Gregor Mendel and the work he did with peas in the 1860s. Since then, and especially over the past 50 years, this notion has assumed the weight, solidity, and rootedness of an immovable object.
But a number of biologists argue that we need to replace this gene-centric view with one that more heavily emphasises the role of gene expression — that we need to see the gene less as an architect and more as a member of a collaborative remodelling and maintenance crew.
in the early 1960s, yet another Brit named William Hamilton (a funny statistician with a shaggy haircut) and an American named George Williams (kind and whipsmart, with an abominable haircut and beard) upped the ante on the gene’s primacy: with fancy maths, they argued that we should view any organism, including any human, as merely a sort of courier for genes and their traits. This flipped the usual thinking. It made the gene vital and the organism expendable. Our genes did not exist for us. We existed for them. We served only to carry these chemical codes forward through time, like those messengers in old sword-and-sandal war movies who run non-stop for days to deliver data and then drop dead. A radical idea. Yet it merely extended the logic of kin selection, in which any gene-courier — say, a mom watching her children’s canoe overturn — would risk her life to let her kin carry forth her DNA.
This notion of the gene as the unit selected, and the organism as a kludged-up cart for carrying it through time, placed the gene smack at the centre of things.
But 15 years after Hamilton and Williams kited [introduced] this idea, it was embraced and polished into gleaming form by one of the best communicators science has ever produced: the biologist Richard Dawkins. In his magnificent book The Selfish Gene (1976), Dawkins gathered all the threads of the modern synthesis — Mendel, Fisher, Haldane, Wright, Watson, Crick, Hamilton, and Williams — into a single shimmering magic carpet.
Unfortunately, say Wray, West-Eberhard and others, it’s wrong.
Wray and West-Eberhard don’t say that Dawkins is dead wrong. They and other evolutionary theorists — such as Massimo Pigliucci, professor of philosophy at the City University of New York; Eva Jablonka, professor of mathematics education at King’s College, London; Stuart Kauffman, professor of biochemistry and mathematics at the University of Vermont; Stuart A Newman, professor of cell biology and anatomy at the New York Medical College; and the late Stephen Jay Gould, to name a few — have been calling for an ‘extended modern synthesis’ for more than two decades. They do so even though they agree with most of what Dawkins says a gene does. They agree, in essence, that the gene is a big cog, but would argue that the biggest cog doesn’t necessarily always drive the other cogs. In many cases, they drive it. The gene, in short, just happens to be the biggest, most obvious part of the trait-making inheritance and evolutionary machine. But not the driver.
In the social wasps that West-Eberhard has been studying in Costa Rica since 1979, many of the most important distinctions among a colony’s individuals rise not from differences in their genomes, which vary little, but from the plasticity born of gene expression. This starts with the queen, who is genetically identical to her thousands of sisters yet whose gene expression makes her not only larger, but singles her out as the colony’s reproductive unit. Likewise with most honeybees. In social honeybees, the differences between workers, guards, and scouts all arise from gene expression, not gene sequence. Individual bees morph from one form to another — worker to guard to scout — by gene expression alone, depending on the needs of the hive.
Like Wray, Pigliucci and others, West-Eberhard has long tried to rescue the centrality of gene expression from the ‘cyclic amnesia’ that she says has ignored 150 years of evidence that gene selection’s role in evolution is overplayed. West-Eberhard is a particularly articulate advocate. Yet she’s frustrated at how little she’s been able to change things.
Yet Dawkins, and with him much of pop science, sticks to the selfish gene. The gene explains all. So far it has worked. The extended synthesis crowd has published scores of papers, quite a few books, and held meetings galore. They have changed the way many biologists think about evolution, at least when those biologists are thinking. But they have scarcely touched the public’s understanding. And they have not found a way to displace a meme so powerful as the selfish gene.
This meme, methinks, forms the true bone of contention and the true obstacle to progress. It’s one of the gruesome beauties of this whole mess that Dawkins himself coined the term meme, and did so in The Selfish Gene. He defined it as a big idea that competes for dominance in a tough environment — an idea that, like a catchy tune or a good joke, ‘propagates itself by leaping from brain to brain’. The selfish-gene meme has done just that. It has made of evolutionary theory a vehicle for its replication. The selfish gene has become a selfish meme.
So of course Eberhard-West can’t change things. Apart from the factors Dobbs mentions, science writers who are any good can write pop Darwin drivel in their sleep. Why fix what ain’t broken (for them)?
There is no “meme” for evidence, and evidence is precisely what matters less and less these days.
Note: Don’t miss the part where Dobbs phones Dawkins, gets the usual plausible spin, and doesn’t just buy it. That’s worth the whole piece, but you have to read it first to get the impact.